High pressure locomotive with interstage superheating



HIGH PRESSURE LOCOMOTIVE WITH INTERSTAGE SUPERHEATING Filed July 9, 1950 2 Sheets-Sheet 1 dig re avffermnww and flan/Izz iffy.

Sept; 27, 1932. HERMANUZ ET AL 1,879,235

HIGH PRESSURE LOCOMOTIVE WITH INTERSTAGE SUPERHEATING Filed July 9, 1950 2 Sheets-Sheet 2 Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE ALFRED HERMANUZ KURT KLUG, OF KASS EL-WILEELMSHOHE, GERMANY, AS-

SIGNORS .TO SCHMIDTSCHE HEISSDAMPF-GESELLSGHAFT MIT BESCHRANKTER EAFTUNG, OF KASSEL-WIIHELMSHOHE, GERMANY, A CORPORATlfON OF GERMANY HIGH PRESSURE LOCOMOTIVE WITH INTERSTAGE SUPERHEATING Application filed July 9 1930, Serial No. 466,799, and in Germany August 31; 1&9.

The object of this invention is a high-pressure compound locomotive with interstage superheating and especially a high-pressure locomotive having a comparatively short 5 smoke tube boiler located in the flow of the fire gases behinda directly or indirectly (e. g. by steam generated in a closed water tube system) heated high-pressure boiler, which generates the high-pressure working steam of e. g. 50t0 100 atmospheres, the said fire tube boiler serving principally as feed water heater and mud collector for the high-pressure boiler and generating only a small quantity of low pressure steam, which low pressure steam may be added to the exhaust of the high-pressure stage of the engine in an interstage superheater or may be used in auxiliary engines after being reheated in a small additional superheater.

To obtain high superheat on locomotives is materially more difiicult than on stationary plants owingto the limited axle load and limited space on locomotives. To overcome those difliculties, the arrangement according to the present invention is characterized by the fact that contrary to all previous smoke tube superheater arrangements for locomotives, the

.ratio of superheating surface and steam raising surface of the smoke tube boiler, which ratio at present is always lower than 1. (one), is inversed and made higher than 1 (one). According to one form of the invention as shown in the drawings the flue tube boiler is fitted throughout or next to throughout with smoke tubes containing more than four superheating tubes, the return bends lying as usual totally'in these smoke tubes. Up to now such superheater arrangements, where all or nearly all smoke tubes are fitted with superheater elements, have only been built as small tube or medium tube superheaters having two or at the most four superheater tubes 1n each smoke tube, while smoke tubes with more than four superheater tubes, though already known, have only been built as so called large flue tube or gross tube superheaters with-2 to 4 rows of these gross tubes arranged above a plurality of empty narrow smoke tubes.

If, according to the invention, the flue or smoke tube preheater of a high-pressure'locomotive with interstage superheating, is built as a new type smoke tube boiler with large flue tubes each accommodating more than four superheater tubes, the uncommon condition mentioned above is arrived at, namely that in the flue tube boiler the ratio super the preheater boiler extends with its water space a considerable part under the steam and water drum of the high-pressure boiler,

so ensuring a better support for the latter andincreasing the stiffness of the whole aggregate, still a relatively small part of'heat is absorbed at the expense of superheat'by the increased water heating surface of the smoke tube boiler, for the water heating surface being .relatively small in comparison with the superheatin-g surface installed, owing to the use of large flue tubes with more than four superheater tubes.

Further heat transmission to the superheater surface owing to the high velocity of the gases very good from the outset and the large'flue tubes can be rolled into the back boiler plate with reduced ends and it is possible to arrange behind this plate an accessible space for the cinders segregating from the slowing down flue gases, by leaving out some rows of high-pressure "steam generating tubes, and this without affecting the superheat and without exposing the return bends in a higher degree to the danger of burning.

Referring to the accompanying draw- 1ngs:

Fig. 1 shows by way of example a longitudinal section through a locomotive, fitted with a superheater arrangement according to the invention,

Fig. 2 is a section on the line A--B in Fig. 1, and

Fig. 3 a section on the line C-D in Fig. 1, the frame and the driving gear being omitted.

Fig. 4 is a top plan view of a portion of the invention.

In the drawings 1 is the high-pressure Water tube boiler which forms the fire box. Adjoining this boiler in the flow of the combustion gases is located the preheater boiler 2. The preheater boiler is traversed by large section smoke tubes 3, each smoke tube accommodating six tubes of two superheaters 4 and 5, as shown on Fig. 2. A steam heated interstage superheater 6 serves for reheating the exhaust steam of the high-pressure cylinder 7, the cylinder being located in the example shown on the drawings on the centre line of the engine. The high-pressure live steam passes through a pipe connection 81 connecting the outlet 8 of the boiler 1 with the inlet 9 of the saturated steam chamber of the highpressure live steam superheater 4 and is highly superheated in the tubes of this superheater. Then the high-pressure steam passes through a pipe connection 10' connecting the outlet 10 of the superheated steam chamber with the inlet 11 of a heating coil or element '(not'shown 011 the drawings) of the interstate superheater 6. After giving off its superheat the high-pressure steam flows from the outlet 12 through a pipe connection 12 to the inlet 14 of the saturated steam chamber of a second flue tube superheater 5 acting as re-superheater and raising the high-pressure steam to the temperature wanted for the high-pressure stage of the engine. The highpressure steam re-superheated passes from the outlet 16 of the superheated steam cham ber of the re-superheater 5 through a pipe connection 16 to the valve chest of the highpressure cylinder 7 The exhaust steam from this cylinder enters the interstate superheater 6 by a pipe connection (not shown) at the inlet 18 and passes superheated from the outlet 19 through a pipe connection (not sh own) to the lateral low-pressure cylinders not shown on the drawings. The large flue tubes 3, accommodating each six superheater tubes, areredueed at the back end and rolled in as shown at 20. The steam generating pipes 22 of the water tube boiler, disposed across the flue in order to protect the smoke tube superheaters against burning, are left out in front of the back end of the preheater boiler 2, giving free an accessible space 23 in which space cinders, owing to'the reduction in the velocity of the gases, will deposit. With this arrangement the water covered surface of each of the large tubes 3 of the reheater boiler 2 is considerably smaller t an the steam touched surface of the six superheating tubes disposed in each flue tube. The front return bends preferably do not extend to the front plate of the preheater boiler and the superheated high-pressure steam becomes too small to add noticeably to the superheat. Under certain circumstances temperature difi'erence might be nought or negative'here and in this case the superheated steam conducting ends of the superheater tubes have to be covered with heat insulating material. The small quantity of lowpressure steam generated in the preheater boiler 2 may be drawnby a pipe connection 24 and supplied to the auxiliary engines (feed pump, air pump and the like) as saturated steam or superheated steam. In the latter case a small superheater could be located in the smoke box or the superheater tubes or this additional superheater could be arranged Within one of the vertical rows of the large flue tubes of the preheater boiler 2. Alternatively the small quantity of low-pressure steam generated in the preheater boiler 2 may be led to the interstage superheater and mixed with the exhaust of the highpressure cylinder of the engine. In the example shown reheating is performed in a steam heated interstage superheater 6, but alternatively within the scope of the invention the exhaust steam of the high-pressure stage of the engine may be directly reheated in a flue tube superheater. In that'case the interstage superheater 6 is omitted and in place of the secondary high-pressure superheater 5 a low-pressure flue tube superheater is located in the large flue tubes of the preheater boiler. In that case the exhaust steam of the high-pressure stage, considering the high temperature of the tube walls, has to be passed throu h an oil separator beforeentering the re eater.

While, in the form shown in the drawings, all of the superheater tubes terminate short of the fire box ends of the flue tubes, it is obvious that many of the same advantages will be gained as long as at least those superheater tubes which are arranged in the flue tubes, whose ends are located in the central or central and in the 'fire box end of the flue tube boiler occupied by the ends of the flue tubes, terminate short of the fire box ends of the tubes. In such a case it is still possible to maintain the free space 23 surrounded by walls and a roof ottom portions of the space and provided with a plurality of flue tubes extending from the fire box superheating tubes of more than one flue gas heated steam superheater within said flue tubes and terminating short of the fire box ends thereof, the ratio of the flue gas touched heating surface of the superheaters to the water covered heating surface of the flue tube boiler being higher than '1 (one).

2. In a locomotive the combination of a water tube boiler forming the fire box and adapted to generate high-pressure steam,

with a flue tube boiler adapted mainly to preheat the feed water ofthe said water tube boiler and provided with a plurality of flue tubes extending from the fire box superheating tubes of more than one flue gas heated steam superheater within said flue tubes and terminating short of the fire box ends thereof, the ratio of the flue gas touched heating surface of the superheaters to the water covered heating surface ofthe flue tube boiler being higher than 1 (one), each of said flue tubes containing more than 4 superheating tubes. 1

3. In a locomotive the combination of a water tube boiler forming the fire box and adapted to generate high-pressure steam, with a flue tube boiler adapted mainly to pre-. heat the feed water of the said water tube boiler and provided with a plurality of flue tubes extending from the fire box superheating tubes of more than one flue gas heated steam superheater within said flue tubes and terminating short of the fire box ends thereof, the ratio of the flue gas touched heating surface of the superheaters to the water covered heating surface of the flue tube boiler being higher than 1 (one), each of said flue tubes containing'more than 4 superhe'atm tubes, a steam heated interstage superheater and means to conduct the high-pressure live steam successively through one of the flue gas heated superheaters, the steam heated interstage superheater and a secondflue gas heated superheater. f V 3 4. In a locomotive, theficombination of a the water covered heating surface of the flue' tube boiler.'

-5. In a locomotive, the .combination of a water tube boiler forming the fire box and adapted to generate high .ressure steam, with a flue tube oiler adapted mainly to preheat the feed water of the said water tube boiler and rovided with a plurality of vertically and orizontally distributed flue tubes extending from the fire box the fire box ends of said flue tubes thereby being located in an extended space substantiall in a vertical lane, superheating tubes o more than one flue gas heated steam superheater within said flue tubes, at least those superheating tubes, in the flue tubes having their ends within the central and lower portions of said s ace terminating short of the fire box ends 0 the flue tubes, the flue gas touched heating surface of the sllperheating tubes being at least as great as he water covered heating surface of the tie tube boiler.

In testimony whereof we have aflixed our signatures.

' ALFRED HERMANUZ.

KURT KLUG.

' loov water tube boiler forming thefire box and adapted to generate high pressure steam, with a flue tube boiler adapted mainly to preheat the feed water of the said water tube boiler' extended space substantially in a vertical plane, superheating. tubesof more than one flue gas heated steam superheater within said flue tubes, at least those superheating tubes "in the flue tubes having their ends within 65 superheating tubes being at least as great as 

